The present disclosure relates generally to high voltage electrical couplings and, more particularly, to interlock systems and methods for protecting high voltage electrical couplings.
Electric machines, such as motors and generators, may be used for a variety of applications, including in connection with automobile power trains. For example, a conventional automobile may use an electric machine as a starting motor for an internal combustion engine, or as an alternator to generate electricity and deliver power to vehicle accessories and/or charge a vehicle's battery. It is also known to use electric machines as traction motors, for example with hybrid/electric vehicles.
Electric machines may be associated with a variety of high voltage couplings. For an electric motor that is coupled to a battery via an inverter, for example, high voltage couplings may exist between the inverter and the electric motor. The electric motor may include a terminal block assembly that receives high voltage wires from the inverter. An interlock cover or lid may be provided to cover the high voltage couplings in the terminal block assembly. When the lid is closed, electricity may be supplied to the couplings to undergo normal operation. When the lid is opened, such as by a service technician, the supply of electricity to the couplings may be terminated. However, even after opening the lid and terminating the supply of electricity to the couplings, the couplings may remain at an elevated voltage for some time before dropping to a safe voltage for handling and servicing by a human.
According to an illustrative embodiment of the present disclosure, a terminal block assembly is provided including a housing defining an interior region, the housing having an access opening into the interior region, a lid having a closed position that closes the access opening and an opened position that exposes the access opening, at least one terminal located within the housing, at least one high voltage wire having a lead that is configured for receipt in the housing to electrically couple the lead to the at least one terminal, and an interlock system. The interlock system includes a lock having a locked position that locks the lid in the closed position and an unlocked position that allows movement of the lid to the opened position, and a controller that commands movement of the lock between the locked position and the unlocked position.
According to another illustrative embodiment of the present disclosure, an electrical circuit is provided including a first high voltage unit, a second high voltage unit, at least one electrical coupling between the first high voltage unit and the second high voltage unit, a terminal block assembly including a housing, the terminal block assembly having a closed configuration to enclose the at least one electrical coupling in the housing and an opened configuration to provide access to the at least one electrical coupling in the housing, and means for locking the terminal block assembly in the closed configuration based on a voltage of the at least one electrical coupling.
According to yet another illustrative embodiment of the present disclosure, a method is provided for servicing a high voltage electrical coupling in a terminal block assembly, the terminal block assembly including a housing and a lid. The method includes the steps of de-energizing the electrical coupling, automatically unlocking the lid when the electrical coupling reaches a predetermined voltage that is safe for human contact, and after the unlocking step, opening the lid to access the electrical coupling in the housing.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.